评估联合弹性成像技术的纤维化相关F指数和炎症活动度相关A指数在分层诊断肝纤维化和炎症程度中的应用价值。

收集2019年9月至2021年4月在复旦大学附属华山医院就诊并接受经皮肝穿刺活检或肝部分切除术并获得病理结果的202例慢性肝病患者，其中49例因肝占位性病变而行肝部分切除术，153例因弥漫性肝病行肝穿刺活检。所有患者在术前进行联合弹性成像检查，获得肝纤维化相关F指数和炎症活动度相关A指数；以病理诊断肝纤维化分期（S0~S4期）和炎症活动分级（G0~G4级）为金标准，使用Kruskal-Wallis秩和检验和Bonferroni校正比较不同纤维化分期的F指数以及不同炎症活动分级的A指数的差异，绘制受试者操作特征曲线，使用DeLong检验比较F指数与剪切波速度、实时组织弹性成像的肝纤维化指数（LFI）、天冬氨酸转氨酶与血小板的比率指数（APRI）在肝纤维化无创诊断中的效能。

肝纤维化分期S0（40例）、S1（42例）、S2（41例）、S3（34例）和S4期（45例）患者的F指数中位数分别为0.89、1.17、1.45、1.75和2.30，相邻纤维化分期之间的F指数中位数比较，差异均具有统计学意义（P＜0.05）。F指数在诊断纤维化分期≥S1、≥S2、≥S3和≥S4的临界值分别为1.14、1.45、1.50和1.63，受试者操作特征曲线下面积（AUC）分别为0.91、0.89、0.90和0.91，均高于LFI（AUC=0.66、0.68、0.69、0.69）与APRI（AUC=0.71、0.68、0.72、0.77），差异均具有统计学意义（P均＜0.05）；F指数诊断纤维化分期≥S1、≥S2期的AUC高于剪切波速度（AUC=0.84、0.85），差异具有统计学意义（P均＜0.05）。炎症活动度分级G0（26例）、G1（86例）、G2（68例）和G3-4（22例）级患者的A指数中位数分别为0.83、0.99、1.29和1.69。相邻等级间的A指数中位数比较，差异均具有统计学意义（P均＜0.05）。A指数区分≥G1、≥G2和≥G3-4的临界值分别为0.87、1.15和1.41，AUC分别为0.86、0.87和0.92。

联合弹性成像技术获得的A指数能很好地评估肝炎症活动度；F指数则校正了肝细胞炎症活动对肝组织硬度测量的影响，能更准确地诊断肝纤维化分期。

To evaluate the application value of fibrosis (F) index and activity (A) index of combinational elastography in stratified diagnosis of liver fibrosis and inflammation.

We collected 202 patients with chronic liver disease who visited Huashan Hospital Affiliated to Fudan University from September 2019 to April 2021. These patients received percutaneous liver biopsy or partial hepatectomy to obtain pathological results. Among them, 49 patients underwent partial hepatectomy due to liver space occupying lesions, and 153 underwent liver biopsy due to diffuse liver disease. All patients underwent combinational elasticity examination before surgery to obtain liver fibrosis-related F index and inflammation activity-related A index. The pathological diagnosis was used as the gold standard for liver fibrosis staging (S0~S4) and inflammatory activity classification (G0~G4). Kruskal-Wallis test and Bonferroni correction test were used to compare the differences in F index among different fibrosis stages and A index among different inflammatory activity grades. DeLong test was used to compare the performance of F index and shear wave velocity, real-time tissue elastography liver fibrosis index (LFI), and aspartate aminotransferase platelet ratio index (APRI) in non-invasive diagnosis of liver fibrosis.

The median F index of patients with liver fibrosis stages S0 (40 cases), S1 (42 cases), S2 (41 cases), S3 (34 cases), and S4 (45 cases) was 0.89, 1.17, 1.45, 1.75, and 2.30, respectively. The difference in the median F index of adjacent fibrosis stages was statistically significant (P＜0.05). The cutoff values of F index in the diagnosis of fibrosis stages ≥S1, ≥S2, ≥S3, and ≥S4 were 1.14, 1.45, 1.50, and 1.63, and the area under the curve (AUC) values were 0.91, 0.89, 0.90, and 0.91, respectively, which were significantly higher than those of LFI (AUC=0.66, 0.68, 0.69, and 0.69, respectively) and APRI (AUC=0.71, 0.68, 0.72, and 0.77, respectively) (P＜0.05). The AUC values of F index in diagnosing fibrosis stages ≥S1 and ≥S2 were significantly higher than those of shear wave velocity (AUC=0.84 and 0.85, respectively) (P＜0.05). The median A index for inflammatory activity grades G0 (26 cases), G1 (86 cases), G2 (68 cases), and G3-4 (22 cases) were 0.83, 0.99, 1.29, and 1.69, respectively. The difference in median A index between adjacent grades was statistically significant (P＜0.05). The cutoff values of A index for distinguishing ≥G1, ≥G2, and ≥G3-4 were 0.87, 1.15, and 1.41, respectively, and the AUC values were 0.86, 0.87, and 0.92, respectively.

The A index obtained by combinational elastography is a good indicator in assessing the grade of liver inflammation activity. F index corrects the influence of inflammatory activity of hepatocytes on the measurement of liver tissue stiffness, and can more accurately diagnose the stage of liver fibrosis.